Moisture curable organopolysiloxane composition

ABSTRACT

The present invention provides curable compositions comprising non-Sn organo-metal catalysts that accelerate the condensation curing of moisture curable silicones/non-silicones. In particular, the present invention provides Mn(III) complexes that are particularly suitable as replacements for organotin for sealant and RTV formulations. The Mn(III) complexes are comparable or superior to organotin such as DBTDL, superior to Mn(II) compounds, and exhibit certain behavior in the presence of components that allow for tuning or adjusting the cure characteristics of the present compositions and provide good adhesion and storage stability.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit from U.S. Provisional Patent ApplicationNo. 61/380,849, entitled “Moisture Curable OrganopolysiloxaneComposition,” filed on Sep. 8, 2010, which is hereby incorporated in itsentirety by reference.

FIELD

The present invention relates to curable compositions comprising curablepolymers having reactive terminal silyl groups and manganese-basedcatalysts. In particular, the present invention provides curablecompositions comprising Mn(III)-based complexes as alternatives toorganotin catalysts.

BACKGROUND

Polymers having reactive terminal silyl groups or compositionscomprising such polymers can be hydrolyzed and condensed in the presenceof water and organometal catalysts. Suitable known catalysts for curablecompositions include organometallic compounds employing metals such asSn, Ti, Zn or Ca. Organotin compounds such as, for example, dibutyltindilaurate (DBTDL) are widely used as condensation cure catalysts toaccelerate the moisture assisted curing of a number of differentpolyorganosiloxanes and non-silicone polymers having reactive terminalsilyl groups such as room temperature vulcanizing (RTV) formulationsincluding RTV-1 and RTV-2 formulations. Environmental regulatoryagencies and directives, however, have increased or are expected toincrease restrictions on the use of organotin compounds in formulatedproducts. For example, while formulations with greater than 0.5 wt. %dibutyltin presently require labeling as toxic with reproductive 1Bclassification, dibutyltin-containing formulations are proposed to becompletely phased out in consumer applications during next 4-6 years.

Alternative organotin compounds such as dioctyltin compounds anddimethyltin compounds can only be considered as a short-term remedialplan, as these organotin compounds may also be regulated in the future.It would be beneficial to identify non-Sn metal catalysts thataccelerate the condensation curing of moisture curable silicones andnon-silicones. Desirably, substitutes for organotin catalysts shouldexhibit properties similar to organotin compounds in terms of curing,storage, and appearance. Non-tin catalysts would also desirably initiatethe condensation reaction of the selected polymers and complete thisreaction upon the surface and may be in the bulk in a desired timeschedule. There are therefore many proposals for the replacement oforganometallic tin compounds by other organometallic compounds. Thesecompounds comprise metals such as Ca, Ce, Bi, Fe, Mo, Mn, Pb, Ti, V, Znand Y. All of these metals have specific advantages and disadvantages inview of replacing tin compounds perfectly. Therefore, there is still aneed to overcome some of the weaknesses of possible metal compounds assuitable catalyst for condensation cure reaction and behavior of uncuredand cured compositions in particular to maintain the ability to adhereonto the surface of several substrates.

The use of manganese (II) complexes as catalysts in siliconecompositions has been described. For example, U.S. Pat. No. 7,115,695describes the use of manganese (II)-carboxylate as a catalyst forcross-linking silyl-capped organic polymers including additionalpromoters. U.S. Pub. No. 2008/0242825 mentions the use of a manganesecatalyst in a process for endcapping polyethers with alkoxysilyl groups.U.S. Pat. No. 5,304,621 discloses the use of a manganese(II)-carboxylate compound as a condensation catalyst forpolyorganosiloxanes having additional organyloxy and hydrogen groups.Other than these general teachings that group manganese complexestogether, there does not appear to be any teachings that differentiatethe catalytic activity exhibited by different manganese complexes.

WO 2009/106719 A1 and WO 2009/106722 A1 disclose among others, e.g.,manganese (III) pentanedionate in a generic list including Bi, Ce, Fe,Mo, Yb compounds and propose the use of these complexes or complexeshaving additional anions as polycondensation catalysts inpolyorganosiloxane compositions, whereby the use and reduction topractice is only disclosed for selected Bi, Ce, Fe, Mo, Sn complexes.The disclosed polyorganosiloxane compositions comprise either only aSiOH terminated combined with ethylsilicate as a crosslinker or aVTMO-terminated polymer, which has been cured with Bi, Ce, Fe, Mo, Sncatalysts in the presence of water or moisture. Another problemnecessary to be solved in the replacement of organo-tin compounds is theproperty of the reactive composition to maintain its ability to cureafter storage in a sealed cartridge, when exposed to humidity or ambientair.

SUMMARY

The present invention provides tin-free, curable compositions comprisingsilyl-terminated polymers and a non-toxic condensation catalyst based onmanganese complexes. In particular, the present invention providescurable compositions employing a Mn(III)-based complex as a condensationcatalyst. In one aspect, the Mn(III)-based catalysts are complexes ofthe Formula (1):Mn^(III)Y_(3-c)A_(c)  (1)wherein Y is a chelating ligand, A is an anion, and c is a numberbetween 0 to 2 or an integer.

In one aspect, the invention provides a curable composition exhibiting arelatively short tack-free time, curing through the bulk, as well aslong storage stability in the cartridge, i.e., in the absence ofhumidity. The inventors have unexpectedly found that Mn(III) compounds,including compounds of formula (1), in combination with certain adhesionpromoter components exhibit curing behavior similar to or even betterthan organotin compounds, and are therefore suitable as replacements fororganotin catalysts in compositions having a reactive, silyl-terminatedpolymer that can undergo condensation reactions such as in RTV-1 sealantand RTV-2 formulations. Specifically, the inventors have found that Mn(III) compounds of formula (1) are comparable or superior to organotinsuch as DBTDL, and superior to Mn (II) complexes when the inventiveadditional promoters are used.

One additional requirement when using selected Mn(III)-compounds is toensure a certain storage stability of the uncured composition in thecartridge, adhesion onto several surfaces and a cure rate in apredictable time scheme.

The inventors have also found that curable compositions employing theMn(III) compounds and additional moderating additives exhibit superiorcuring behavior compared to compositions comprising Mn (II) carboxylatesor pure Mn (III) complexes. Moreover, applicants have found that thecombination of the Mn (III) catalysts and the additional additives mayprovide curable compositions allowing for a controlled curing time thatis shorter or longer than that of organotin based compositions.

In one aspect, the present invention provides a curable compositioncomprising a moisture curable composition comprising a polymer component(A) comprising a reactive terminal silyl group; a cross-linker component(B); a catalyst component (C) comprising manganese (III) (Mn(III))wherein the catalyst component is a compound of the formula:Mn^(III)Y_(3-c)A_(c)where in Y is a chelating ligand, A is an anion, and c is a numberbetween 0 to 2 or an integer thereof; and 0.1 to 5 wt. % of an adhesionpromoter (D).

In one aspect, the present invention provides a composition for forminga cured polymer composition comprising (A) a polymer having at least areactive silyl group; (B) a crosslinker or chain extender chosen from analkoxysilane, an alkoxysiloxane, an oximosilane, an oximosiloxane, anenoxysilane, an enoxysiloxane, an aminosilane, a carboxysilane, acarboxysiloxane, an alkylamidosilane, an alkylamidosiloxane, anarylamidosilane, an arylamidosiloxane, an alkoxyaminosilane, analkaryaminosiloxane, an alkoxycarbamatosilane, analkoxycarbamatosiloxane, and combinations of two or more thereof; (C)about 0.01-7 parts per weight per 100 parts per weight of the polymer(A) of a catalyst selected from the group of organometallic compounds orsalts of manganese (III) (Mn-III); (D) at least one adhesion promoterchosen from a silane or siloxane other than the compounds listed under(B); (E) optionally, a filler component; and (F) at least one acidiccompound chosen from a phosphate ester, a phosphonate, a phosphite, aphosphine, a sulfite, a pseudohalogenide, a branched alkyl carboxylicacid, or a combination of two or more thereof.

According to one embodiment, the metal catalyst component (C) comprisesa Mn(III) complex of the formula: Mn^(III)Y_(3-c)A_(c), wherein Y is achelating ligand chosen from a diketonate, a diamine, a triamine, anaminoacetate, a nitriloacetate, a bypyridin, a glyoxime, or acombination of two or more thereof; and A is an anion, and c is a numberbetween 0 to 2 or an integer.

According to one embodiment, the chelating agent Y comprises asubstituted or unsubstituted diketonate.

According to one embodiment, the anion A is chosen from a branchedC₄-C₁₉-alkyl carboxylic acid, a C₄-C₁₂-alkylsulfonate, or a combinationthereof.

According to one embodiment, the component (F) is chosen from a monoester of a phosphate; a phosphonate of the formula (R³O)PO(OH)₂,(R³O)P(OH)₂, or R³P(O)(OH)₂ where R³ is a C₁-C₁₈-alkyl, aC₂-C₂₀-alkoxyalkyl, phenyl, a C₇-C₁₂-alkylaryl, a poly(C₂-C₄-alkylene)oxide ester or its mixtures with diesters; a branched alkyl C₄-C₁₄-alkylcarboxylic acid; or a combination of two or more thereof.

In another aspect, the polymer (A) has the formula: [R¹ _(a)R²_(3-a)Si—Z—]_(n)—X—Z—SiR¹ _(a)R² _(3-a). In another embodiment, X ischosen from a polyurethane; a polyester; a polyether; a polycarbonate; apolyolefin; a polypropylene; a polyesterether; and a polyorganosiloxanehaving units of R₃SiO_(1/2), R₂SiO, RSiO_(3/2), and/or SiO_(4/2), n is 0to 100, a is 0 to 2, R and R¹ can be identical or different at the sameSi-atom and chosen from a C₁-C₁₀-alkyl; a C₁-C₁₀ alkyl substituted withone or more of Cl, F, N, O or S; a phenyl; a C₇-C₁₆ alkylaryl; a C₇-C₁₆arylalkyl; a C₂-C₄ polyalkylene ether; or a combination of two or morethereof. In yet another aspect, R² is chosen from OH, a C₁-C₈-alkoxy, aC₂-C₁₈-alkoxyalkyl, an oximoalkyl, an enoxyalkyl, an aminoalkyl, acarboxyalkyl, an amidoalkyl, an amidoaryl, a carbamatoalkyl, or acombination of two or more thereof, and Z is a bond, a divalent unitselected from the group of a C₁-C₈ alkylene, or O.

According to one embodiment, the crosslinker component (B) is chosenfrom tetraethylorthosilicate (TEOS), a polycondensate of TEOS,methyltrimethoxysilane (MTMS), vinyl-trimethoxysilane,methylvinyldimethoxysilane, dimethyldiethoxysilane,vinyltriethoxysilane, tetra-n-propylorthosilicate,vinyltris(methylethylketoxime)silane,methyltris(methylethylketoxime)silane, trisacetamidomethylsilane,bisacetamidodimethylsilane, tris(N-methyl-acetamido)methylsilane,bis(N-methylacetamido)dimethylsilane,(N-methylacetamido)methyldialkoxysilane, trisbenzamidomethylsilane,trispropenoxymethylsilane, alkyldialkoxyamidosilanes,alkylalkoxybisamidosilanes, CH₃Si(OC₂H₅)₁₋₂(NHCOR)₂₋₁,(CH₃Si(OC₂H₅)(NCH₃COC₆H₅)₂, CH₃Si(OC₂H₅)—(NHCOC₆H₅)₂,methyldimethoxy(ethylmethylketoximo)silane;methylmethoxybis-(ethylmethylketoximo)silane;methyldimethoxy(acetaldoximo)silane;methyldimethoxy(N-methylcarbamato)silane;ethyldimethoxy(N-methylcarbamato)silane;methyldimethoxyisopropenoxysilane; trimethoxyisopropenoxysilane;methyltri-iso-propenoxysilane; methyldimethoxy(but-2-ene-2-oxy)silane;methyldimethoxy(1-phenylethenoxy)silane;methyldimethoxy-2(1-carboethoxypropenoxy)silane;methylmethoxydi-N-methylaminosilane; vinyldimethoxymethylaminosilane;tetra-N,N-diethylaminosilane; methyldimethoxymethylaminosilane;methyltricyclohexylaminosilane; methyldimethoxyethylaminosilane;dimethyldi-N,N-dimethylaminosilane; methyldimethoxyisopropylaminosilanedimethyldi-N,N-diethylaminosilane;ethyldimethoxy(N-ethylpropionamido)silane;methyldimethoxy(N-methylacetamido)silane;methyltris(N-methylacetamido)silane;ethyldimethoxy(N-methylacetamido)silane;methyltris(N-methylbenzamido)silane;methylmethoxybis(N-methylacetamido)silane;methyldimethoxy(caprolactamo)silane;trimethoxy(N-methylacetamido)silane;methyldimethoxyethylacetimidatosilane;methyldimethoxypropylacetimidatosilane;methyldimethoxy(N,N′,N′-trimethylureido)silane;methyldimethoxy(N-allyl-N′,N′-dimethylureido)silane;methyldimethoxy(N-phenyl-N′,N′-dimethylureido)silane;methyldimethoxyisocyanatosilane; dimethoxydiisocyanatosilane;methyldimethoxythioisocyanatosilane;methylmethoxydithioisocyanatosilane, or a combination of two or morethereof.

According to one embodiment, the adhesion promoter component (D) ischosen from an aminoalkyltrialkoxysilane, anaminoalkylalkyldialkoxysilane, a bis(alkyltrialkoxysilyl)amine, atris(alkyltrialkoxysilyl)amine, a tris(alkyltrialkoxysilyl)cyanuarate,and a tris(alkyltrialkoxy-silyl)isocyanuarate, or a combination of twoor more thereof.

According to one embodiment, the composition comprises about 1 to about10 wt. % of the crosslinker component (B) based on 100 wt. % of thepolymer component (A).

According to one embodiment, the crosslinker component (B) is chosenfrom a silane or a siloxane, the silane or siloxane having two or morereactive groups that can undergo hydrolysis and/or condensation reactionwith polymer (A) or on its own in the presence of water and component(F).

According to one embodiment, the polymer component (A) is chosen from apolyorganosiloxane comprising divalent units of the formula [R₂SiO] inthe backbone, wherein R is chosen from a C₁-C₁₀-alkyl; a C₁-C₁₀ alkylsubstituted with one or more of Cl, F, N, O or S; a phenyl; a C₇-C₁₆alkylaryl; a C₇-C₁₆ arylalkyl; a C₂-C₄ polyalkylene ether; or acombination of two or more thereof.

According to one embodiment, the polymer component (A) has the formula:R² _(3-a)R¹ _(a)Si—Z—[R₂SiO]_(x)[R¹ ₂SiO]_(y)—Z—SiR¹ _(a)R² _(3-a)whereby x is 0 to 10000; y is 0 to 1000; a is 0 to 2; R is methyl. Inanother aspect, R¹ is chosen from a C₁-C₁₀-alkyl; a C₁-C₁₀ alkylsubstituted with one or more of Cl, F, N, O or S; a phenyl; a C₇-C₁₆alkylaryl; a C₇-C₁₆ arylalkyl; a C₂-C₄ polyalkylene ether; or acombination of two or more thereof, and other siloxane units may bepresent in amounts less than 10 mol. % preferably methyl, vinyl, phenyl.In yet another embodiment, R² is chosen from OH, a C₁-C₈-alkoxy, aC₂-C₁₈-alkoxyalkyl, an oximoalkyl, an enoxyalkyl, an aminoalkyl, acarboxyalkyl, an amidoalkyl, an amidoaryl, a carbamatoalkyl, or acombination of two or more thereof, and Z is —O—, bond, or —C₂H₄—.

According to one embodiment, the composition further comprises a solventchosen from an alkylbenzene, a trialkyphosphophate, a triarylphosphate,a phthalic acid ester, an arylsulfonic acid ester having aviscosity-density constant (VDC) of at least 0.86 that is miscible witha polyorganosiloxanes and catalyst component (C), a polyorganosiloxanedevoid of reactive groups and having a viscosity of less than 2000 mPa·sat 25° C., or a combination of two or more thereof.

According to one embodiment, the composition is provided as a one partcomposition.

According to one embodiment, the composition comprises 100 pt. wt ofcomponent (A), 0.1 to about 10 pt. wt of at least one crosslinker (B),0.01 to about 7 pt. wt. of a catalyst (C), 0.1 to about 5 pt. wt. of anadhesion promoter (D), 0 to about 300 pt. wt of component (E), 0.01 toabout 8 pt. wt. of component (F) whereby this composition can be storedin the absence of humidity and is curable in the presence of humidityupon exposure to ambient air.

According to one embodiment, the composition is a two-part compositioncomprising: (i) a first portion comprising the polymer component (A),optionally the filler component (E), and optionally the acidic compound(F); and (ii) a second portion comprising the crosslinker (B), thecatalyst component (C), the adhesive promoter (D), and the acidiccompound (F), whereby (i) and (ii) are stored separately until appliedfor curing by mixing of the components (i) and (ii).

According to one embodiment, portion (i) comprises 100% wt of component(A), and 0 to 70 pt. wt. of component (E); and portion (ii) comprises0.1 to 10 pt. wt. of at least one crosslinker (B), 0.01 to 7 pt. wt. ofa catalyst (C), 0 to 5 pt. wt. of an adhesion promoter (D), and 0.02 to3 pt. wt. component (F).

In another aspect, the present invention provides a method of providinga cured material comprising exposing the composition to ambient air.

According to one embodiment, a method of providing a cured materialcomprises combining the first portion and the second portion and curingthe mixture.

According to one embodiment, the composition is stored in a sealedcartridge or flexible bag having outlet nozzles for extrusion and/orshaping of the uncured composition prior to cure.

In still another aspect, the present invention provides a cured polymermaterial formed from the composition.

According to one embodiment, the cured polymer material is in the formof an elastomeric or duromeric seal, an adhesive, a coating, anencapsulant, a shaped article, a mold, and an impression material.

The compositions are found to exhibit good storage stability and adhereto a variety of surfaces. In one embodiment, the curable compositionsexhibit excellent adherence to thermoplastic surfaces, includingpolyacrylate and polymethylmethacrylate (PMMA) surfaces.

DETAILED DESCRIPTION

The present invention provides a curable composition employing amanganese (Mn(III)) complex as a condensation catalyst. The Mn(III)complexes identified in the present invention exhibit similar orsuperior curing properties as compared to compositions employingorganotin compounds such as DBTDL in terms of accelerating moistureassisted condensation curing of silicones to result in cross-linkedsilicones, which can be used as sealants and RTVs (Room-TemperatureVulcanized Rubber). The non-toxic nature of these manganese compoundsmakes them more attractive and practical than organotin catalysts, giventhe forthcoming strict regulations on organotin catalysts.

It has been found that different manganese complexes exhibit a varyingdegree of catalytic activity, depending upon the oxidation state ofmanganese metal. In particular, applicants have found that Mn(III)complexes function better as catalysts as compared to Mn(II) complexes.Additionally, the ligands attached to manganese may affect the degree ofcatalytic activity. The Mn(III) complexes have been found to mostly worksatisfactorily in most of typical sealant and RTV formulations, whichadditionally contain other ingredients.

In comparison to DBTDL, which is a free flowing liquid, the Mn(III)complexes are solid in nature and, hence, are usually dispersed with theaid of an organic solvent. The inventors have found that the choice ofsolvent may play a role in assuring uniform dispersion of catalyst, andthereby altering curing speed. Various aspects of the Mn(III) complexesare described further herein.

The present invention provides a curable composition comprising apolymer component (A) comprising a reactive terminal silyl group, across-linker component (B), a catalyst component (C) comprising aMn(III)-based complex, and a adhesion promoter component (D). Thecompositions may further include other optional components as may beused in curable compositions such as, for example, a filler component(E), a cure rate modifying component or a stabilizer (F) for extendedstorage for uncured composition and/or auxiliary components (G).

The polymer component (A) may be a liquid or solid-based polymer havinga reactive terminal silyl group. The polymer component (A) is notparticularly limited and may be chosen from any cross-linkable polymeras may be desired for a particular purpose or intended use. Non-limitingexamples of suitable polymers for the polymer component (A) includepolyorganosiloxanes (A1) or organic polymers free of siloxane bonds(A2), wherein the polymers (A1) and (A2) comprise reactive terminalsilyl groups. In one embodiment, the polymer component (A) may bepresent in an amount of from about 10 to about 90 wt. % of the curablecomposition. In one embodiment, the curable composition comprises about100 pt. wt. of the polymer component (A).

As described above, the polymer component (A) may include a wide rangeof polyorganosiloxanes. In one embodiment, the polymer component maycomprise one or more polysiloxanes and copolymers of formula (2):[R¹ _(a)R² _(3-a)Si—Z—]_(n)—X—Z—SiR¹ _(a)R² _(3-a)  (2)R¹ may be chosen from saturated C₁-C₁₂ alkyl (which can be substitutedwith one or more of a halogen (e.g., Cl, F, O, S or N atom), C₅-C₁₆cycloalkyl, C₂-C₁₂ alkenyl, C₇-C₁₆ arylalkyl, C₇-C₁₆ alkylaryl, phenyl,C₂-C₄ polyalkylene ether, or a combination of two or more thereof.Exemplary preferred groups are methyl, trifluoropropyl and/or phenylgroups.

R² may be a group reactive to protonated agents such as water and may bechosen from OH, C₁-C₈-alkoxy, C₂-C₁₈-alkoxyalkyl, amino, alkenyloxy,oximoalkyl, enoxyalkyl, aminoalkyl, carboxyalkyl, amidoalkyl, amidoaryl,carbamatoalkyl or a combination of two or more thereof. Exemplary groupsfor R² include OH, alkoxy, alkenyloxy, alkyloximo, alkylcarboxy,alkylamido, arylamido, or a combination of two or more thereof.

Z may be a bond, a divalent linking unit selected from the group ofO_(1/2), hydrocarbons which can contain one or more O, S or N atom,amide, urethane, ether, ester, urea units or a combination of two ormore thereof. If the linking group Z is a hydrocarbon group then Z islinked to the silicon atom over a SiC bond. In one embodiment Z ischosen from a C₁-C₁₄ alkylene.

X is chosen from a polyurethane; a polyester; a polyether; apolycarbonate; a polyolefin; a polypropylene; a polyesterether; and apolyorganosiloxane having units of R₃SiO_(1/2), R₂SiO, RSiO_(3/2),and/or SiO_(4/2), where R is chosen from a C₁-C₁₀-alkyl; a C₁-C₁₀ alkylsubstituted with one or more of Cl, F, N, O or S; a phenyl; a C₇-C₁₆alkylaryl; a C₇-C₁₆ arylalkyl; a C₂-C₄ polyalkylene ether; or acombination of two or more thereof X may be a divalent or multivalentpolymer unit selected from the group of siloxy units linked over oxygenor hydrocarbon groups to the terminal silyl group comprising thereactive group R² as described above, polyether, alkylene, isoalkylene,polyester or polyurethane units linked over hydrocarbon groups to thesilicon atom comprising one or more reactive groups R² as describedabove. The hydrocarbon group X can contain one or more heteroatoms suchas N, S, O or P forming amides, esters, ethers urethanes, esters, ureas.In one embodiment, the average polymerization degree (P_(n)) of X shouldbe more than 6, e.g. polyorganosiloxane units of R₃SiO_(1/2), R₂SiO,RSiO_(3/2), and/or SiO_(4/2). In formula (2), n is 0-100; desirably 1,and a is 0-2, desirably 0-1.

Non-limiting examples of the components for unit X includepolyoxyalkylene polymers such as polyoxyethylene, polyoxypropylene,polyoxybutylene, polyoxyethylene-polyoxypropylene copolymer,polyoxytetramethylene, or polyoxypropylene-polyoxybutylene copolymer;ethylene-propylene copolymer, polyisobutylene, polychloroprene,polyisoprene, polybutadiene, copolymer of isobutylene and isoprene,copolymers of isoprene or butadiene and acrylonitrile and/or styrene, orhydrocarbon polymer such as hydrogenated polyolefin polymers produced byhydrogenating these polyolefin polymers; polyester polymer manufacturedby a condensation of dibasic acid such as adipic acid or phthalic acidand glycol, polycarbonates, or ring-opening polymerization of lactones;polyacrylic acid ester produced by radical polymerization of a monomersuch as C₂-C₈-alkyl acrylates, vinyl polymers, e.g., acrylic acid estercopolymer of acrylic acid ester such as ethyl acrylate or butyl acrylateand vinyl acetate, acrylonitrile, methyl methacrylate, acrylamide orstyrene; graft polymer produced by polymerizing the above organicpolymer with a vinyl monomer; polysulfide polymer; polyamide polymersuch as Nylon 6® produced by ring-opening polymerization ofε-caprolactam, Nylon 6.6 produced by polycondensation ofhexamethylenediamine and adipic acid, etc., Nylon 12 produced byring-opening polymerization of ε-aminolauro-lactam, copolymericpolyamides, polyurethanes, or polyureas.

Particularly suitable polymers include, but are not limited to,polysiloxanes, polyoxyalkylenes, saturated hydrocarbon polymers such aspolyisobutylene, hydrogenated polybutadiene and hydrogenatedpolyisoprene, or polyethylene, polypropylene, polyester, polycarbonates,polyurethanes, polyurea polymers and the like. Furthermore, saturatedhydrocarbon polymer, polyoxyalkylene polymer and vinyl copolymer areparticularly suitable due to their low glass transition temperaturewhich provide a high flexibility at low temperatures, i.e. below 0° C.

The reactive silyl groups in formula (2) can be introduced by employingsilanes containing a functional group which has the ability to react byknown methods with unsaturated hydrocarbons via hydrosilylation, orreaction of SiOH, aminoalkyl, HOOC-alkyl, HO-alkyl or HO-aryl, HS-alkylor -aryl, Cl(O)C-alkyl or -aryl, epoxyalkyl or epoxycycloalkyl groups inthe prepolymer to be linked to a reactive silyl group via condensationor ring-opening reactions. Examples of the main embodiments include thefollowing:

(i) siloxane prepolymers having a SiOH group that can undergo acondensation reaction with a silane (L-group)SiR¹ _(a)R² _(3-a) wherebya siloxy bond ≡Si—O—SiR¹ _(a)R² _(3-a) is formed while the additionproduct of the leaving group (L-group) and hydrogen is released (L-group+H);(ii) silanes having an unsaturated group that is capable of reacting viaa hydrosilylation or a radical reaction with a SiH group or radicallyactivated groups of a silane such as SiH or an unsaturated group; and(iii) silanes including organic or inorganic prepolymers having OH, SH,amino, epoxy, —COCl, —COOH groups, which can react complementarily withepoxy, isocyanato, OH, SH, cyanato, carboxylic halogenides, reactivealkylhalogenides, lactones, lactams, or amines, that is to link thereactive prepolymer with the organofunctional silanes to yield a silylfunctional polymer.

Silanes suitable for method (i) include alkoxysilanes, especiallytetraalkoxysilanes, di- and trialkoxysilanes, di- and triacetoxysilanes,di- and triketoximato-silanes, di- and trialkenyloxysilanes, di- andtricarbonamidosilanes, wherein the remaining residues at the siliconatom of the silane are substituted or unsubstituted hydrocarbons. Othernon-limiting silanes for method (i) include alkyltrialkoxysilanes, suchas vinyltrimethoxysilane, methyltrimethoxysilane, propyltrimethoxysilaneaminoalkyltrimethoxysilane, ethyltriacetoxysilane, methyl- orpropyltriacetoxysilane, methyltributanonoximosilane,methyltripropenyloxysilane, methyltribenzamidosilane, ormethyltriacetamidosilane. Prepolymers suitable for reaction under method(i) are SiOH-terminated polyalkylsiloxanes, which can undergo acondensation reaction with a silane having hydrolysable groups attachedto the silicon atom. Exemplary SiOH-terminated polyalkydisiloxanesinclude polydimethylsilaxanes.

Suitable silanes for method (ii) include alkoxysilanes, especiallytrialkoxysilanes (HSi(OR)₃) such as trimethoxysilane, triethoxysilane,methyldiethoxysilane, methyldimethoxysilane, and phenyldimethoxysilane;methyldiacetoxysilane and phenyldiacetoxysilane. Hydrogenchlorosilanesare in principle possible but are less desirable due to the additionalreplacement of the halogen through an alkoxy, acetyoxy group, etc. Othersuitable silanes include organofunctional silanes having unsaturatedgroups which can be activated by radicals, such as vinyl, allyl,mercaptoalkyl or acrylic groups. Non-limiting examples includevinyltrimethoxysilane, mercaptopropyltrimethoxysilane,methyacryloxypropyltrimethoxysilane. Prepolymers suitable for reactionunder method (ii) include vinyl terminated polyalkylsiloxanes,preferably polydimethylsiloxanes, hydrocarbons with unsaturated groupswhich can undergo hydrosilylation or can undergo radically inducedgrafting reactions with a corresponding organofunctional group of asilane comprising an e.g. unsaturated hydrocarbon or a —SiH group.

Another method for introducing silyl groups into hydrocarbon polymerscan be the copolymerization of unsaturated hydrocarbon monomers with theunsaturated groups of silanes. The introduction of unsaturated groupsinto a hydrocarbon prepolymer may include, for example, the use ofalkenyl halogenides as chain stopper after polymerization of the siliconfree hydrocarbon moiety.

Desirable reaction products between the silanes and prepolymers includethe following structures:—SiR₂O—SiR₂—CH₂—CH₂—SiR¹ _(a)R² _(3-a), or (hydrocarbon)-[Z—SiR¹ _(a)R²_(3-a)]₁₋₅₀Suitable silanes for method (iii) include, but are not limited to,alkoxysilanes, especially silanes having organofunctional groups to bereactive to —OH, —SH, amino, epoxy, —COCl, or —COOH.

In one embodiment, these silanes have an isocyanatoalkyl group such asgamma-isocyanatopropyltrimethoxysilane,gamma-isocyanatopropylmethyldimethoxysilane,gamma-isocyanatopropyltriethoxysilane,gamma-glycidoxypropylethyldimethoxysilane,gamma-glycidoxypropyltrimethoxysilane,gamma-glycidoxypropyltrimethoxysilane,gamma-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,epoxylimonyltrimethoxysilane, N-(2-aminoethyl)-aminopropyltrimethoxysilane gamma-aminopropyltriethoxysilane,gamma-aminopropyltrimethoxysilane,gamma-aminopropylmethyldimethoxysilane,gamma-aminopropylmethyldiethoxysilane and the like.

In one embodiment, it is desirable to select either blocked amines orisocyanates (Z′—X)_(n)—Z′ for carrying out first a complete mixing andthen the following coupling reaction. Examples of blocking agents aredisclosed in EP 0947531 and other blocking procedures that employheterocyclic nitrogen compounds such as caprolactam or butanone oxime,or cyclic ketones referred to in U.S. Pat. No. 6,827,875 both of whichare incorporated herein by reference in their entirety.

Examples of suitable prepolymers for a reaction under method (iii)include, but are not limited to, polyalkylene oxides having OH groups,preferably with a high molecular weight (Mw) (weight average molecularweight>6000 g/mol) and a polydispersity Mw/Mn of less than 1.6;urethanes having remaining NCO groups, such as NCO functionalizedpolyalkylene oxides, especially blocked isocyanates. Prepolymersselected from the group of hydrocarbons having —OH, —COOH, amino, epoxygroups, which can react complementarily with an epoxy, isocyanato,amino, carboxyhalogenide or halogenalkyl group of the correspondingsilane having further reactive groups useful for the final cure.

Suitable isocyanates for the introduction of a NCO group into apolyether may include tolulene diisocyanate, diphenylmethanediisocyanate, or xylene diisocyanate, or aliphatic polyisocyanate suchas isophorone diisocyanate, or hexamethylene diisocyanate.

The polymerization degree of the unit X depends on the requirements ofviscosity and mechanical properties of the cured product. If X is apolydimethylsiloxane unit, the average polymerization degree based onthe number average molecular weight Mn is preferably 7 to 5000 siloxyunits, preferably 200-2000 units. In order to achieve a sufficienttensile strength of >5 MPa, an average polymerization degree Pn of >250is suitable whereby the polydimethylsiloxanes have a viscosity of morethan 1000 mPa·s at 25° C. If X is a hydrocarbon unit other than apolysiloxane unit the viscosity with respect to the polymerizationdegree is much higher.

Examples of the method for synthesizing a polyoxyalkylene polymerinclude, but are not limited to, a polymerization method using an alkalicatalyst such as KOH, a polymerization method using a transition metalcompound porphyrin complex catalyst such as complex obtained by reactingan organoaluminum compound, a polymerization method using a compositemetal cyanide complex catalyst disclosed, e.g., in U.S. Pat. No.3,427,256; U.S. Pat. No. 3,427,334; U.S. Pat. No. 3,278,457; U.S. Pat.No. 3,278,458; U.S. Pat. No. 3,278,459; U.S. Pat. No. 3,427,335; U.S.Pat. No. 6,696,383; and U.S. Pat. No. 6,919,293.

If the group X is selected from hydrocarbon polymers, then polymers orcopolymers having isobutylene units are particularly desirable due toits physical properties such as excellent weatherability, excellent heatresistance, and low gas and moisture permeability.

Examples of the monomers include olefins having 4 to 12 carbon atoms,vinyl ether, aromatic vinyl compound, vinylsilanes, and allylsilanes.Examples of the copolymer component include 1-butene, 2-butene,2-methyl-1-butene, 3-methyl-1-butene, pentene, 4-methyl-1-pentene,hexene, vinylcyclohexene, methyl vinyl ether, ethyl vinyl ether,isobutyl vinyl ether, styrene, α-methylstyrene, dimethylstyrene,β-pinene, indene, and for example but not limited tovinyltrialkoxysilanes, e.g. vinyltrimethoxysilane,vinylmethyldichlorosilane, vinyldimethylmethoxysilane,divinyldichlorosilane, divinyldimethoxysilane, allyltrichlorosilane,allylmethyldichlorosilane, allyldimethylmethoxysilane,diallyldichlorosilane, diallyldimethoxysilane,gamma-methacryloyloxypropyltrimethoxysilane, andgamma-methacryloyloxy-propyl-methyldimethoxysilane.

In one embodiment, the polymer component (A) may be a polymer of formula(3):R² _(3-a)R¹ _(a)Si—Z—[R₂SiO]_(x)[R¹ ₂SiO]_(y)—Z—SiR¹ _(a)R² _(3-a)  (3)where R¹, R², and Z are defined as above with respect to formula (2); Ris C₁-C₆-alkyl (an exemplary alkyl being methyl); a is 0-2, x is 0 toabout 10,000; preferably 11 to about 2500; and y is 0 to about 1,000;preferably 0 to 500. In one embodiment, Z in a compound of formula (3)is a bond or a divalent C₂ to C₁₄-alkylene group, especially preferredis —C₂H₄—.

Non-limiting examples of suitable polysiloxane-containing polymers (A1)include, for example, silanol-stopped polydimethylsiloxane, silanol oralkoxy-stopped polyorganosiloxanes, e.g., methoxystoppedpolydimethylsiloxane, alkoxy-stoppedpolydimethylsiloxane-polydiphenylsiloxane copolymer, and silanol oralkoxy-stopped fluoroalkyl-substituted siloxanes such as poly(methyl3,3,3-trifluoropropyl)siloxane and poly(methyl3,3,3-trifluoropropyl)siloxane-polydimethyl siloxane copolymer. Thepolyorganosiloxane component (A1) may be present in an amount of about10 to about 90 wt. % of the composition or 100 pt. wt. In one preferredembodiment, the polyorganosiloxane component has an average chain lengthin the range of about 10 to about 2500 siloxy units, and the viscosityis in the range of about 10 to about 500,000 mPa·s at 25 C.

Alternatively, the composition may include silyl-terminated organicpolymers (A2) that are free of siloxane units, and which undergo curingby a condensation reaction comparable to that of siloxane containingpolymers (A1). Similar to the polyorganosiloxane polymer (A1), theorganic polymers (A2) that are suitable as the polymer component (A)include a terminal silyl group. In one embodiment, the terminal silylgroup may be of the formula (4):—SiR¹ _(d)R² _(3-d)  (4)where R¹, R², and a are as defined above.

Examples of suitable siloxane free organic polymers include, but are notlimited to, silylated polyurethane (SPUR), silylated polyester,silylated polyether, silylated polycarbonate, silylated polyolefins likepolyethylene, polypropylene, silylated polyesterether and combinationsof two or more thereof. The siloxane-free organic polymer may be presentin an amount of from about 10 to about 90 wt. % of the composition orabout 100 pt. wt.

In one embodiment, the polymer component (A) may be a silylatedpolyurethane (SPUR). Such moisture curable compounds are known in theart in general can be obtained by various methods including (i) reactingan isocyanate-terminated polyurethane (PUR) prepolymer with a suitablesilane, e.g., one possessing both hydrolyzable functionality at thesilicon atom, such as, alkoxy etc., and secondly activehydrogen-containing functionality such as mercaptan, primary orsecondary amine, preferably the latter, etc., or by (ii) reacting ahydroxyl-terminated PUR (polyurethane) prepolymer with a suitableisocyanate-terminated silane, e.g., one possessing one to three alkoxygroups. The details of these reactions, and those for preparing theisocyanate-terminated and hydroxyl-terminated PUR prepolymers employedtherein can be found in, amongst others: U.S. Pat. Nos. 4,985,491;5,919,888; 6,207,794; 6,303,731; 6,359,101; and 6,515,164 and publishedU.S. Patent Application Nos. 2004/0122253 and US 2005/0020706(isocyanate-terminated PUR prepolymers); U.S. Pat. Nos. 3,786,081 and4,481,367 (hydroxyl-terminated PUR prepolymers); U.S. Pat. Nos.3,627,722; 3,632,557; 3,971,751; 5,623,044; 5,852,137; 6,197,912; and6,310,170 (moisture-curable SPUR (silane modified/terminatedpolyurethane) obtained from reaction of isocyanate-terminated PURprepolymer and reactive silane, e.g., aminoalkoxysilane); and, U.S. Pat.Nos. 4,345,053; 4,625,012; 6,833,423; and published U.S. PatentApplication 2002/0198352 (moisture-curable SPUR obtained from reactionof hydroxyl-terminated PUR prepolymer and isocyanatosilane). The entirecontents of the foregoing U.S. patent documents are incorporated byreference herein. Other examples of moisture curable SPUR materialsinclude those described in U.S. Pat. No. 7,569,653, the disclosure ofwhich is incorporated by reference in its entirety.

The polysiloxane composition may further include a crosslinker or achain extender as component (B). In one embodiment, the crosslinker isof the formula (5):R¹ _(a)SiR² _(4-a)  (5)wherein R² may be as described above, R¹ may be as described above, anda is 0-3. Alternatively, the cross-linker component may be acondensation product of formula (5) wherein one or more but not all R²groups are hydrolyzed and released in the presence of water and thenintermediate silanols undergo a condensation reaction to give a Si—O—Sibond and water. The average polymerization degree can result in acompound having 2-10 Si units.

As used herein, the term crosslinker includes a compound including anadditional reactive component having at least 2 hydrolysable groups andless than 3 silicon atoms per molecule not defined under (A). In oneembodiment, the crosslinker or chain extender may be chosen from analkoxysilane, an alkoxysiloxane, an oximosilane, an oximosiloxane, anenoxysilane, an enoxysiloxane, an aminosilane, a carboxysilane, acarboxysiloxane, an alkylamidosilane, an alkylamidosiloxane, anarylamidosilane, an arylamidosiloxane, an alkoxyaminosilane, analkaryaminosiloxane, an alkoxycarbamatosilane, analkoxycarbamatosiloxane, an imidatosilane, a ureidosilane, anisocyanatosilane, a thioisocyanatosilane, and combinations of two ormore thereof. Examples of suitable cross-linkers include, but are notlimited to, tetraethylorthosilicate (TEOS); methyltrimethoxysilane(MTMS); methyltriethoxysilane; vinyltrimethoxysilane;vinyltriethoxysilane; methylphenyldimethoxysilane;3,3,3-trifluoropropyltrimethoxysilane; methyltriacetoxysilane;vinyltriacetoxysilane; ethyltriacetoxysilane; di-butoxydiacetoxysilane;phenyltripropionoxysilane; methyltris(methylethylketoxime)silane;vinyltris(methylethylketoxime)silane;3,3,3-trifluoropropyltris(methylethylketoxime)silane;methyltris(isopropenoxy)silane; vinyltris(isopropenoxy)silane;ethylpolysilicate; dimethyltetraacetoxydisiloxane;tetra-n-propylorthosilicate; methyldimethoxy(ethylmethylketoximo)silane;methylmethoxybis-(ethylmethylketoximo)silane;methyldimethoxy(acetaldoximo)silane;methyldimethoxy(N-methylcarbamato)silane;ethyldimethoxy(N-methylcarbamato)silane;methyldimethoxyisopropenoxysilane; trimethoxyisopropenoxysilane;methyltri-iso-propenoxysilane; methyldimethoxy(but-2-ene-2-oxy)silane;methyldimethoxy(1-phenylethenoxy)silane;methyldimethoxy-2(1-carboethoxypropenoxy)silane;methylmethoxydi-N-methylaminosilane; vinyldimethoxymethylaminosilane;tetra-N,N-diethylaminosilane; methyldimethoxymethylaminosilane;methyltricyclohexylaminosilane; methyldimethoxyethylaminosilane;dimethyldi-N,N-dimethylaminosilane; methyldimethoxyisopropylaminosilanedimethyldi-N,N-diethylaminosilane.ethyldimethoxy(N-ethylpropionamido)silane;methyldimethoxy(N-methylacetamido)silane;methyltris(N-methylacetamido)silane;ethyldimethoxy(N-methylacetamido)silane;methyltris(N-methylbenzamido)silane;methylmethoxybis(N-methylacetamido)silane;methyldimethoxy(caprolactamo)silane;trimethoxy(N-methylacetamido)silane;methyldimethoxyethylacetimidatosilane;methyldimethoxypropylacetimidatosilane;methyldimethoxy(N,N′,N′-trimethylureido)silane;methyldimethoxy(N-allyl-N′,N′-dimethylureido)silane;methyldimethoxy(N-phenyl-N′,N′-dimethylureido)silane;methyldimethoxyisocyanatosilane; dimethoxydiisocyanatosilane;methyldimethoxythioisocyanatosilane;methylmethoxydithioisocyanatosilane, or combinations of two or morethereof. The crosslinker may be present in an amount from about 1 toabout 10 wt. % of the composition or from about 0.1 to about 10 pt. wt.per 100 pt. wt. of the polymer component (A).

Additional alkoxysilanes in an amount greater than 0.1 wt. % ofcomponent and (A) that are not consumed by the reaction between theprepolymer Z′—X—Z′ and which comprise additional functional groupsselected from R⁴ can also work as adhesion promoter and are defined andcounted under component (D).

The curable compositions further comprise an organometal catalyst (C).As described herein, the catalyst (C) comprises a Mn(III) complex. Theinventors have unexpectedly found that Mn(III) complexes exhibit asuperior degree of catalytic activity over other manganese complexessuch as Mn or Mn(II) complexes. Mn(III) complexes are found to worksatisfactorily in most of the compositions, e.g., typical sealant RTV1or RTV2 formulations, comprising polymers having reactive terminalgroups, which may additionally contain other ingredients. In comparisonto DBTDL, which is a free flowing liquid, the Mn(III) complexes may beeither solid or liquid in nature. In the case of solid Mn(III)complexes, these are usually dispersed with the aid of an organicsolvent.

In one embodiment, the catalysts component (C) is a Mn(III) complex ofthe formula (1):Mn^(III)Y_(3-c)A_(c)  (1)wherein Y is a chelating ligand, A is an anion, and c=0-2.

The chelating ligand Y may be chosen from diketonates, diamines,triamines, aminoacetates, nitriloacteates, bipyridins, glyoximes,combinations of two or more thereof, and the like. Examples of suitablechelating ligands include, but are not limited to,acetylacetonate-2,4-pentanedione (‘AA’ or ‘acac’); hexanedione-2,4;heptanedione-2,4; heptanedione-3,5; ethyl-3-pentanedione-2,4;methyl-5-hexanedione-2,4; octanedione-2,4; octanedione-3,5; dimethyl-5,5hexanedione-2,4; methyl-6-heptanedione-2,4;dimethyl-2,2-nonanedione-3,5; dimethyl-2,6-heptanedione-3,5;2-acetylcyclohexanone (Cy-acac); 2,2,6,6-tetramethyl-3,5-heptanedione(t-Bu-acac); 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (F-acac)];benzoylacetone; dibenzoylmethane; 3-methyl-2,4-pentadione;3-acetyl-pentane-2-one; 3-acetyl-2-hexanone; 3-acetyl-2-heptanone;3-acetyl-5-methyl-2-hexanone; stearoylbenzoylmethane;octanoylbenzoylmethane; 4-t-butyl-4′-methoxy-dibenzoylmethane;4,4′-dimethoxy-dibenzoylmethane; 4,4′-di-tert-butyl-dibenzoylmethane,hexafluoroacetylacetone, or a combination of two or more thereof.

The anion A in formula (1) is not particularly limited and may be chosenfrom anions including, but not limited to, halides, hydroxide, oxide,peroxide, ozonide, hydrosulfide, alkoxides, alkyl thio, nitride,acetate, amide, carboxylate, cyanide, cyanate, thiocyanate, carbonate,hydrogen carbonate and the like. Some specific examples of suitableanions include, but are not limited to, F⁻, Cl⁻, (I₃)⁻, [ClF₂]⁻, [IF₆]⁻,(ClO)⁻, (ClO₂)⁻, (ClO₃)⁻, (ClO₄)⁻, (OH)⁻, (SH)⁻, (SeH)⁻, (O₂)⁻, (O₃)⁻,(HS₂)⁻, (CH₃O)⁻, (C₂H₅O)⁻, (C₃H₇O)⁻, (CH₃S)⁻, (C₂H₅S)⁻, (C₂H₄ClO)⁻,(C₆H₅O)⁻, (C₆H₅S)⁻, [C₆H₄(NO₂)O]⁻, (HCO₂)⁻, (C₇H₁₅CO₂)⁻, (CH₃CO₂)⁻,(CH₃CH₂CO₂)⁻, (N₃)⁻, (CN)⁻, (NCO)⁻, (NCS)⁻, (NCSe)⁻, (NH₂)⁻, (PH₂)⁻,(ClHN)⁻, (Cl₂N)⁻, (CH₃NH)⁻, (HN═N)″, (H₂N—NH)⁻, (HP═P)⁻, (H₂PO)⁻,(H₂PO₂)⁻, and the like. In one embodiment, the anion A is chosen from abranched C₄-C₁₄-alkyl carboxylic acid, a C₄-C₁₂-alkylsulfonate, or acombination thereof.

In one embodiment, the catalyst compound (C) comprises Mn(III)hexafluoroacetyl-acetonate (Mn(III)HFAA). In another embodiment, thecatalysts component (C) comprises Mn(III) acetylacetonate (Mn(III) AA).

In one embodiment, the Mn(III) complex may be added to the compositionin an amount of from about 0.01 to about 7.0 pt. wt. related to 100 partper weight of component (A). In another embodiment the Mn(III) complexmay be added in an amount of from about 0.1 to about 1.0 pt. wt. Instill another embodiment, the Mn(III) complex may be added in an amountof from about 0.2 to about 0.4 pt. wt. An increase in the amount ofMn(III) complex as a catalyst may increase the rate of the surface curetime and the bulk or complete cure time for the composition.Furthermore, the amount of the Mn(III) complex added to the compositionmay affect the viscosity of the composition. Particularly, an increasein the amount of the Mn(III) complex may increase the final viscosity ofthe composition.

The composition may further include an adhesion promoter component (D)that is different to component (A) or (B). In one embodiment, theadhesion promoter (D) may be an organofunctional silane comprising thegroup R⁴, e.g., aminosilanes, and other silanes that are not identicalto the silanes of component (B), or are present in an amount whichexceeds the amount of silanes necessary for endcapping the polymer (A).The amount of non-reacted silane (B) or (D) in the reaction for making(A) can be defined in that after the endcapping reaction the freesilanes are evaporated at a higher temperature up to 200° C. and vacuumup to 1 mbar to be more than 0.1 wt. % of (A).

Thus, some selected amines can advantageously be added to fine-tune therate of Mn(III) complex catalyzed condensation curing ofsilicone/non-silicone polymer containing reactive silyl groups, asdesired.

In one embodiment, the composition comprises an adhesion promoter (D)comprising a group R⁴ as described by the general formula (6):R⁴ _(e)R¹ _(d)Si(OR³)_(4-d-e)  (6)where R⁴ is E-(CR⁵ ₂)_(f)—W—(CH₂)_(f)—; R¹ is as described above; d is0, 1 or 2; e=1, 2 or 3; d+e=1 to 2; and f is 0 to 8, and may beidentical or different.

Non-limiting examples of suitable compounds include:E¹-(CR⁵ ₂)_(f)—W—(CH₂)_(f)SiR¹ _(d)(OR³)_(3-d)  (6a), or (6d)E²-[(CR⁵ ₂)_(f)—W—(CH₂)_(f)SiR¹ _(d)(OR³)_(3-d)]_(p)  (6b) or (6f)where p=2-3.

The group E may be selected from either a group E¹ or E². E¹ may beselected from a monovalent group comprising amine, —NH₂, —NHR,—(NHC₂H₅)₁₋₁₀NHR, NHC₆H₅, halogen, pseudohalogen, unsaturated aliphaticgroup with up to 14 carbon atoms, epoxy-group-containing aliphatic groupwith up to 14 carbon atoms, cyanurate-containing group, and anisocyanurate-containing group.

E² may be selected from a group comprising of a di- or multivalent groupconsisting of amine, polyamine, isocyanurate-containing and anisocyanurate-containing group, sulfide, sulfate, phosphate, phosphiteand a polyorganosiloxane group, which can contain R⁴ and OR³ groups; Wis selected from the group consisting of a single bond, a heteroatomicgroup selected from —COO—, —O—, epoxy, —S—, —CONH—, —HN—CO—NH— units; R⁵is selected from hydrogen and R as defined above, R¹ may be identical ordifferent as defined above, R³ is selected from the group, whichconsists of C₁-C₈-alkoxy, such as methoxy, ethoxy, C₃-C₁₂-alkoxyalkyl,C₂-C₂₂-alkylcarboxy and C₄-C₁₀₀-polyalkylene oxide may be identical ordifferent.

Non-limiting examples of component (D) include:

wherein R and d are as defined above. Examples of component (D) includecompounds of the formulas (6a-6k). Furthermore the formula (6b) ofcompounds (D) shall comprise compounds of the formula (6l):

wherein: R, R¹, R³, and R⁴ are as defined above; R⁶ is hydrogen, R,linear and branched C₃-C₁₆ alkyl, C₅-C₁₄ cycloalkyl, phenyl, and phenylsubstituted with C₁-C₈ alkyl; s is 0-6 (and in one embodiment desirably0); u is 0-10 (in one embodiment desirably 0-5); and s+u is 10 or less.In one embodiment, R⁴ is selected from:

An exemplary group of adhesion promoters are selected from the groupwhich consists of amino group-containing silane coupling agents, whichcan also be used as the cure rate modifying component (F). The aminogroup-containing silane adhesion promoter agent (D) is a compound havinga group containing a silicon atom bonded to a hydrolyzable group(hereinafter referred to as a hydrolyzable group attached to the siliconatom) and an amino group. Specific examples thereof include the samesilyl groups with hydrolyzable groups described above. Among thesegroups, the methoxy group and ethoxy group are particularly suitable.The number of the hydrolyzable groups may be 2 or more, and particularlysuitable are compounds having 3 or more hydrolyzable groups.

Examples of other suitable adhesion promoter (D) include, but are notlimited to N-(2-aminoethyl)aminopropyltrimethoxysilanegamma-aminopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane,bis(gamma-trimethoxysilypropyl)amine,N-phenyl-gamma-aminopropyltrimethoxysilane,triaminofunctionaltrimethoxysilane,gamma-aminopropylmethyldimethoxysilane,gamma-aminopropylmethyldiethoxysilane,methacryloxypropyltrimethoxysilane, methylaminopropyltrimethoxysilane,gamma-glycidoxypropylethyldimethoxysilane,gamma-glycidoxypropyltrimethoxysilane,gamma-glycidoxyethyltrimethoxysilane,gamma-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,beta-(3,4-epoxycyclohexyl)ethylmethyl-dimethoxysilane,epoxylimonyltrimethoxysilane, isocyanatopropyltriethoxysilane,isocyanatopropyltrimethoxysilane, isocyanatopropylmethyldimethoxysilane,beta-cyano-ethyl-trimethoxysilane,gamma-acryloxypropyl-trimethoxysilane,gamma-methacryloxypropyl-methyldimethoxysilane, alpha,omega-bis-(aminoalkyl-diethoxysilyl)-polydimethylsiloxanes (Pn=1-7),alpha, omega-bis-(aminoalkyl-diethoxysilyl)-octa-methyltetrasiloxane,4-amino-3,3-dimethyl-butyl-trimethoxysilane, andN-ethyl-3-tri-methoxy-silyl-2-methylpropanamine,3-(diethyl-aminopropyl)-trimethoxysilane combinations of two or morethereof, and the like. Particularly suitable adhesion promoters includebis(alkyltrialkoxysilyl)amines and tris(alkyltrialkoxysilyl)aminesincluding, but not limited to, bis(3-propyltrimethoxysilyl)amine andtris(3-propyltrimethoxysilyl)amine.

Also it is possible to use derivatives obtained by modifying them, forexample, amino-modified silyl polymer, silylated amino polymer,unsaturated aminosilane complex, phenylamino long-chain alkyl silane andaminosilylated silicone. These amino group-containing silane couplingagents may be used alone, or two or more kinds of them may be used incombination.

The curable compositions of the present invention may further comprisean alkoxysilane or blend of alkoxysilanes as an adhesion promoter (D).The adhesion promoter may be a combination blend ofN-2-aminoethyl-3-aminopropyltrimethoxysilane and1,3,5-tris(trimethoxy-silylpropyl)isocyanurate and others.

The adhesion promoter (D) may be present in an amount of from about 0.1to about 5.0 pt. wt. based on 100 parts of the polymer component (A). Inone embodiment, the adhesion promoter may be present in an amount offrom about 0.15 to about 2.0 pt. wt. In another embodiment, the adhesionpromoter may be present in an amount of from about 0.5 to about 1.5 pt.wt of the polymer component (A). This defines the amount of (D) incomposition of (A) wherein the content of free silanes coming from theendcapping of polymer (A) is smaller than 0.1 wt. %.

The present compositions may further include a filler component (E). Thefiller component(s) (E) may have different functions, such as to be usedas reinforcing or semi-reinforcing filler, i.e., to achieve highertensile strength after curing having in addition the ability to increasethe viscosity establish pseudoplasticity/shear thinning, and thixotropicbehavior as well as non-reinforcing fillers acting mainly as a volumeextender. The reinforcing fillers are characterized by having a specificsurface area of more than 50 m²/g related BET-surface, whereby thesemi-reinforcing fillers have a specific surface area in the range of10-50 m²/g. So-called extending fillers have preferably a specificsurface of less than 10 m²/g according to the BET-method and an averageparticle diameter below 100 μm. In one embodiment of thesemi-reinforcing filler is a calcium carbonate filler, the reinforcingfiller is a silica filler, or a mixture thereof. Examples of suitablereinforcing fillers include, but are not limited to fumed silicas orprecipitated silica, which can be partially or completely treated withorganosilanes or siloxanes to make them less hydrophilic and decreasethe water content or control the viscosity and storage stability of thecomposition. These fillers are named hydrophobic fillers. Tradenames areAerosil®, HDK®, Cab-O—Sil® etc.

Examples of suitable extending fillers include, but are not limited to,ground silicas (Celite™), precipitated and colloidal calcium carbonates(which are optionally treated with compounds such as stearate or stearicacid); reinforcing silicas such as fumed silicas, precipitated silicas,silica gels and hydrophobized silicas and silica gels; crushed andground quartz, cristobalite, alumina, aluminum hydroxide, titaniumdioxide, zinc oxide, diatomaceous earth, iron oxide, carbon black,powdered thermoplastics such as acrylonitrile, polyethylene,polypropylene, polytetrafluoroethylene and graphite or clays such askaolin, bentonite or montmorillonite (treated/untreated), and the like.

The type and amount of filler added depends upon the desired physicalproperties for the cured silicone/non-silicone composition. As such, thefiller may be a single species or a mixture of two or more species. Theextending fillers can be present from about 0 to about 300 wt. % of thecomposition related to 100 parts of component (A). The reinforcingfillers can be present from about 5 to about 60 wt. % of the compositionrelated to 100 parts of component (A), preferably 5 to 30 wt. %.

The inventive compositions further comprise a cure rate modifyingcomponent (F) or stabilizers for an extended storage time in a sealedcartridge. The component (F) may be present in an amount of from about0.01 to about 5 wt. % of the composition. In another embodiment 0.01 toabout 8 parts per weight (pt. wt.) per 100 pt. wt. of component (A) areused, more preferably 0.02 to 3 pt. wt. per 100 pt. wt. of component (A)and most preferably 0.02 to 1 pt. wt. per 100 pt. wt. of component (A)are used. The component (F) may be chosen from compounds designated as(F1) and (F2). The compounds (F1) may be selected from primary,secondary or tertiary amines comprising saturated or unsaturatedhydrocarbons, such as C₁-C₃₀-alkyl, C₂-C₃₀-alkenyl, C₇-C30-alkylaryl,alkylenaryl arylalkyl, C₃-C₁₀-alkylene oxide or C₄-C₃₀₀-polyalkyleneoxide groups, which can be substituted or interrupted with one or moreO-, P- and S-atoms. The cure rate modifying component (F1) may beemployed to modify the rate at which the composition undergoes curing.Depending on the material employed, the cure rate modifying componentmay accelerate or retard curing of the composition. Thus, the cure ratemodifying component may allow for control or tuning of the composition'scuring characteristics.

The compounds (F2) may be an acidic compound chosen from variousphosphate esters, phosphonates, phosphites, phosphines, sulfites,pseudohalogenides, branched alkyl carboxylic acids, combinations of twoor more thereof, and the like. The compounds (F2) are useful asstabilizers in order to ensure a longer storage time when sealed in acartridge before use in contact with ambient air. Especiallyalkoxy-terminated polysiloxanes can lose the ability to cure afterstorage in a cartridge and show e.g. decreased hardness under curingconditions. It is therefore desirable to add compounds of the formula(7), which can extend storage time or ability to cure over months.O═P(OR⁷)_(3-r)(OH)_(r)  (7)whereby r is 0, 1 or 2, and R⁷ is selected from the group a linear orbranched and optionally substituted C₁-C₃₀-alkyl groups, linear orbranched, C₅-C₁₄-cycloalkyl groups, C₆-C₁₄-aryl groups, C₆-C₃₁ alkylarylgroups, linear or branched C₂-C₃₀-alkenyl groups or linear or branchedC₁-C₃₀-alkoxy-alkyl groups, C₄-C₃₀₀-polyalkenylene oxide groups(polyethers), such as Marlophor® N5 acid, triorganylsilyl- and diorganyl(C₁-C₈)-alkoxysilyl groups. The phoshates can include also mixtures ofprimary and secondary esters. Non-limiting examples of suitablephosphonates include 1-hydroxyethane-(1,1-iphosphonate) (HEDP),aminotrimethylene phosphonate (ATMP), nitrolotris(methylphosphonate)(NTMP), diethylenetriaminepentakismethylene phosphonate (DTPMP),1,2-diaminoethanetetrakismethylene phosphonate (EDTMP), andphosphonobutanetricarbonate (PBTC).

In another embodiment, a compound of the formula o═P(OR⁷)_(2-t)(OH)_(t)may be added where t is 1 or 2, and R⁷ is as defined above or di- ormultivalent hydrocarbons with one or more amino group.

Another type are phosphonic acid compounds of the formula O═PR⁷(OH)₂such as alkyl phosphonic acids preferably hexyl or octyl phosphonicacid.

In one embodiment, the acidic compound may be chosen from is chosen froma mono ester of a phosphate; a phosphonate of the formula (R³O)PO(OH)₂,(R³O)P(OH)₂, or R³P(O)(OH)₂ where R³ is a C₁-C₁₈-alkyl, aC₂-C₂₀-alkoxyalkyl, phenyl, a C₇-C₁₂-alkylaryl, a poly(C₂-C₄-alkylene)oxide ester or its mixtures with diesters, etc.

In another embodiment, the acidic compound is a branched alkylC₄-C₁₉-alkyl carboxylic acids, including C₅-C₁₉ acids with alphatertiary carbon, or a combination of two or more thereof. Examples ofsuch suitable compounds include, but are not limited to, Versatic™ Acid,Lauric Acid, Steric Acid, etc. In one embodiment, the acidic compoundmay be a mixture comprising branched alkyl carboxylic acids. In oneembodiment, the acidic compound is a mixture of mainly tertiaryaliphatic C₁₀ carboxylic acids.

Applicants have found that the combination of a Mn(III) catalyst and anacidic compound as the cure modifying agent may provide a curablecomposition that provides a cured polymer exhibiting a tack-free time,hardness, and/or cure time comparable to compositions made using tincatalysts, but that provide better adhesion compared to materials madeusing tin catalysts.

In one embodiment, the curable composition includes an amine compound asthe cure rate modifying component. The amine compounds may be selectedfrom a group of amines that is different than component (A), (B), (D) or(F). Amine compounds are sometimes employed as promoters to accelerate acompositions curing characteristics, even in compositions employingMn(II) complexes as catalysts such as described in U.S. Pat. No.7,115,695. The inventors have found, however, that amine compounds inthe present compositions employing a catalyst composition comprising aMn(III) catalyst retards the surface curing characteristics of thecomposition as compared to a composition employing the Mn(III)-catalystwithout the cure rate modifying component, while still providing forbulk curing similar to a composition that does not include the cure ratemodifying component.

Amine compounds suitable as the cure rate modifying component include,but are not limited to, aliphatic primary amines such as methylamine,ethylamine, propylamine, isopropylamine, butyl amine, amylamine,hexylamine, octylamine, 2-ethylhexylamine, nonylamine, decylamine,laurylamine, pentadecylamine, cetylamine, stearylamine, andcyclohexylamine; aliphatic secondary amines such as dimethylamine,diethylamine, dipropylamine, diisopropylamine, dibutylamine,diamylamine, dioctylamine, di(2-ethylhexyl)amine, didecylamine, dilaurylamine, dicetylamine, distearylamine, methylstearylamine,ethylstearylamine, and butylstearylamine; aliphatic tertiary amines suchas triethylamine, triamylamine, trihexylamine, and trioctylamine;aliphatic unsaturated amines such as triallylamine and oleylamine;aromatic amines such as laurylaniline, stearylaniline, triphenylamine,N,N-dimethylaniline, and dimethylbenzylaniline; and other amines such asmonoethanolamine, diethanolamine, triethanolamine, dimethylaminoethanol,diethylenetriamine, triethylenetetramine, tetraethylenepentamine,benzylamine, diethylaminopropylamine, xylylenediamine, ethylenediamine,hexamethylenediamine, dodecamethylenediamine, dimethylethylenediamine,triethylenediamine, guanidine, diphenylguanidine,N,N,N′,N′-tetramethyl-1,3-butanediamine,N,N,N′,N′-tetramethylethylenediamine,2,4,6-tris(dimethylaminomethyl)phenol, morpholine, N-methylmorpholine,2-ethyl-4-methylimidazole, and 1,8-diazabicyclo(5,4,0)undecene-7 (DBU).Particularly preferred are amine such as N,N-dimethyldodecyl amine(DMDA); octadecylamine (stearylamine) (ODA).

The curable composition may also include auxiliary substances (G) suchas plastizers, pigments, stabilizers, anti-microbial or fungicides,biocides and/or solvents. Preferred plastizers for reactivepolyorganosiloxanes (A) are selected from the group ofpolyorganosiloxanes having chain length of 10-300 siloxy units.Preferred are trimethylsilyl terminated polydimethylsiloxanes having aviscosity of 100-1000 mPa·s at 25° C. The choice of optional solvents(dispersion media or extenders) may have a role in assuring uniformdispersion of the catalyst, thereby altering curing speed. Such solventsinclude polar and non-polar solvents such as toluene, hexane,chloroform, methanol, ethanol, isopropyl alcohol, acetone, ethylmethylketone, dimethylformamide (DMF), dimethyl sulfoxide (DMSO). Water can bean additional component (G) to accelerate fast curing 2 partcompositions RTV 2-K, whereby the water can be in one part of the 2compositions. Particularly suitable non-polar solvents include, but arenot limited to, toluene, hexane and the like if the solvents shouldevaporate after cure and application. In another embodiment, thesolvents include high boiling hydrocarbons such as alkylbenzenes,phtalic acid esters, arylsulfonic acid esters, trialkyl- ortriarylphosphate esters, which have a low vapor pressure and can extendthe volume providing lower costs. Examples cited by reference may bethose of U.S. Pat. No. 6,599,633; U.S. Pat. No. 4,312,801. The solventcan be present in an amount of from about 20 to about 99 wt. % of thecatalyst composition.

In one embodiment, a composition in accordance with the presentinvention comprises: 100 pt. wt. polymer component (A); about 0.1 toabout 10 pt. wt crosslinker component (B); about 0.01 to about 7 pt. wtcatalyst component (C); about 0.1 to about 5, in one embodiment 0.15-1pt. wt, of an adhesion promoter component (D); about 0 to about 300 pt.wt filler component (E); about 0.01 to about 7 pt. wt cure ratemodifying component or stabilizer (F); optionally 0 to about 15 pt. wtcomponent (G), where the pt. wt. of components (B)-(G) are each based on100 parts of the polymer component (A).

It will be appreciated that the curable compositions may be provided aseither a one-part composition or a two-part composition. A one-partcomposition refers to a composition comprising a mixture of the variouscomponents described above. A two-part composition may comprise a firstportion and a second portion that are separately stored and subsequentlymixed together just prior to application for curing. In one embodiment,a two-part composition comprises a first portion (P1) comprising apolymer component (A) and a crosslinker component (B), and a secondportion (P2) comprising the catalyst component (C) comprising theMn(III) complex. The first and second portions may include othercomponents (F) and/or (G) as may be desired for a particular purpose orintended use. For example, in one embodiment, the first portion (P1) mayoptionally comprise an adhesion promoter (D) and/or a filler (E), andthe second portion (P2) may optionally comprise auxiliary substances(G), a cure rate modifying component (F), and water (G).

In one embodiment, a two-part composition comprises (i) a first portioncomprising the polymer component (A), optionally the filler component(E), and optionally the acidic compound (F); and (ii) a second portioncomprising the crosslinker (B), the catalyst component (C), the adhesivepromoter (D), and the acidic compound (F), where portions (i) and (ii)are stored separately until applied for curing by mixing of thecomponents (i) and (ii).

The curable compositions may be used in a wide range of applicationsincluding as materials for sealing, mold making, adhesives, coatings insanitary rooms, glazing, prototyping, joint seal between differentmaterials, e.g. sealants between ceramic or mineral surfaces andthermoplastics, paper release, impregnation, and the like. A curablecomposition in accordance with the present invention comprising aMn(III) complex as a catalyst may be suitable for a wide variety ofapplications such as, for example, a general purpose and industrialsealant, potting compound, caulk, adhesive or coating for constructionuse, insulated glass (IG), structural glazing (SSG), where glass sheetsare fixed and sealed in metal frame; caulks, adhesives for metal plates,car bodies, vehicles, electronic devices and the like. Furthermore, thepresent composition may be used either as a one-part RTV-1K or as atwo-part room temperature vulcanizing (RTV-2K) formulation which canadhere onto broad variety of metal, mineral, ceramic, rubber or plasticsurfaces.

Curable compositions comprising Mn(III) catalyst compounds may befurther understood with reference to the following Examples.

EXAMPLES

For example a mixture according to composition (a) is prepared byadmixing of 22.5 g of silanol-stopped polydimethylsiloxane polymer(Silanol, 30,000 cps at 25° C.) as component (A) and 2.5 g ofmethyltrimethoxysilane (MTMS) as component (B) taken in a plastic cupwas mixed thoroughly, using a Hauschild mixer for 1 min. To thismixture, the respective manganese compound as component (C) dissolved inan appropriate solvent was added. The resultant mixture was subsequentlymixed in the Hauschild mixer for 1 minute. The mixed formulation waspoured into a Teflon mold (length×breadth×depth˜10 cm×10 cm×1 cm) placedinside a fume hood. The surface curing (Tack-free-time-TFT) and bulkcuring was monitored as a function of time (maximum of 7 days).

Procedure for Making Representative Formulations (a) to (f):

Six representative formulations were made by mixing various ingredients(in parts) as given in Table 1 below.

TABLE 1 Component A b c d E f g Methylstopped polydimethylsiloxane, (100G — — — 5 cps) Silanol-stopped polydimethylsiloxane, (3000 A — 65.58  —cps) Silanol-stopped polydimethylsiloxane, A — — 100 (10000 cps)Silanol-stopped polydimethylsiloxane, A 22.5 7.29 — (30000 cps)Silanol-stopped polydimethylsiloxanes- A — — 115  — polydiphenylsiloxanecopolymer, 5500 cps Silanol-stopped polydimethylsiloxanes- A — — 40 —polydiphenylsiloxane copolymer, 12000 cps Dimethoxysilyl stopped A 100100 polydimethylsiloxane² Silylated polyurethane)³ A 100Tetraethylorthosilicate, TEOS B — 3.15   2.33 Methyltrimethoxysilane,MTMS B  2.5 5 vinyltris(methylethylketoxime)silane B — — — 3.3methyltris(methylethylketoxime)silane B — — — 2.2 N-(2- D — — — 1.4aminoethyl)aminopropyltrimethoxysilane HMDZ treated fumed silica BET 200m²/g E — — — 12 18 Calcium Carbonate E — 29.4  — — Iron oxide G — — 88 —Diatomaceous earth Celite ™ E — — 28 — Water G — 0.21 — — ²Madeaccording to Example I of U.S. Pat. No. 4,599,394; ³Made according tomethod (b) of U.S. Pat. No. 7,569,653 B2; HMDZ = hexamethyldisilazane.General Experimental Procedure for Evaluation in RepresentativeFormulation:

To 50 g of one of formulations (b), (c), or (d) taken in plastic cup,the respective manganese compound dissolved in appropriate solvent wasadded and the resultant mixture was mixed thoroughly in the Hauschildmixer for 2 minutes The mixed formulation was poured into a Teflon mold(length×breadth×depth˜10 cm×10 cm×1 cm) placed inside a fume hood. Thesurface curing (TFT) and bulk curing was monitored as a function of time(maximum of 7 days). The composition (b) represents a 2 part (RTV2)composition; part P1 in this case contained all ingredients exceptcatalyst (C); P2 was catalyst (C).

General Experimental Procedure for Evaluation in Dimethoxysilyl StoppedPolydimethylsiloxane (or) Silylated Polyurethane:

To 25 g of one of formulations (a), (e), or (0 taken in a plastic cup,the manganese compound dissolved in appropriate solvent was added andthe resultant mixture was mixed thoroughly in the Hauschild mixer for 2minutes The mixed formulation was poured into a Teflon mold(length×breadth×depth˜10 cm×10 cm×1 cm) placed inside a fume hood. Thesurface curing (TFT) and bulk curing was monitored as a function of time(maximum of 7 days).

Measurement of Surface Curing (TFT) and Bulk Curing:

The surface cure was denoted by tack free time (TFT). In a typical TFTmeasurement, a stainless steel (SS) weight (weighing ˜10 g) was placedon the surface of the formulation spread on the Teflon mold to infer thetackiness of the surface, as whether any material is adhered to thesurface of the SS weight or not. TFT is defined as the time taken forgetting a non-tacky surface. Bulk curing is the time taken for completecuring of formulation throughout the thickness (i.e. Top to bottom) andit is monitored as a function of time (visual inspection).

Measurement of the Storage Stability:

The ready to cure mixtures (a) to (g) in particular (e) and (g) areplaced in separate sealed polyethylene cartridges in order to inhibitcure through ambient (humid) air. These cartridges were stored at 50 and100° C. for several days. Then the compositions (a) to (g) have beenreleased to ambient air by extrusion onto a sheet or mold out of Teflonfor starting the cure reaction after storage and measuring theTack-Free-Time, the time for completing the cure if possible and ° ShoreA hardness in order to determine, to what extent the compositionsmaintained performance after storage under accelerated conditions. Theincreased temperature for the storage test should simulate the storageeffect at room temperature (25° C. 50% relative humidity) over longertimes in a kind of time lapse.

Screening of Manganese Compounds:

Several metal compounds were screened as catalysts. The typicalscreening experiment involves model formulations containing a silanolterminated polydimethylsiloxane as component (A), crosslinker ascomponent (B) and catalyst (C) for manufacture formulation (a).Accordingly the other formulations (b) to (f) are made selecting otherpolymer components (A) as shown in table 1. The catalyst was typicallyadded at 2 loadings. The surface cure time (TFT) and bulk/completecuring were used as a screening parameter to down select the effectivecatalyst. The screening results are tabulated below. From the screeningexperiments, the inventors found that the Mn(III) complexes as component(C) were superior to other manganese complexes. As shown in Table 2, thereactivity order for the tested complexes isMn(III)AA>Mn(III)TMH>Mn(II)AA>>Mn(II)HFAA, Mn2-EH, MnNaph (abbreviationsat the end of table 2).

Manganese compounds having different oxidation states and containingdifferent ligand groups were screened. Among the six manganese compoundsscreened the result showed the Mn(III)AA had TFT of 2 min and completelycured in 1 day (Examples 9-10) while DBTDL had TFT of 14 min andcompletely cured in 1 day (comparative example C1 and C2). The presentresults show that the manganese (III) (Examples 9-10) has bettercatalytic activity compare to manganese (II). Between the two manganese(III) compounds screened the results show that the Mn(III)AA has highercatalytic activity compare to Mn(III)TMH (Examples 9-12). Among theacetylacetonates, the results showed that the manganese (III) has highercatalytic activity compared to manganese (II) compounds (Examples 5-6,9-10). Mn(III)AA had a TFT of 2 min and completely cured in 1 day(Examples 9-10) while the Mn(II)AA containing formulations are partiallycured in 7 days (Examples 5-6). Among the different Mn(II) compounds,the results showed Mn(II)AA has little catalytic activity while othersare inactive in the concentration tried.

TABLE 2 Complete Catalyst Curing amount TFT Color of after ExampleCatalyst (in g) [min] formulation n days C1 DBTDL 0.2  14 Colorless 1 C2DBTDL 0.4  14 Colorless 1 1 MnNaph 0.2 — Peach >7* 2 MnNaph 0.4 —Peach >7* 3 Mn2-EH 0.2 — Peach orange >7* 4 Mn2-EH 0.4 — Peachorange >7* 5 Mn(II)AA 0.2 — Blackish brown  >7** 6 Mn(II)AA 0.4 —Blackish brown  >7** 7 Mn(II)HFAA 0.2 — Pale yellow >7* 8 Mn(II)HFAA 0.4— Yellow >7* 9 Mn(III)AA 0.2  2 Brown 1 10 Mn(III)AA 0.4  2 Brown 1 11Mn(III)TMH 0.2 300 Blackish brown 2 12 Mn(III)TMH 0.4 330 Blackish brown2 Catalyst weight per 100 g of formulation (a) C1; C2 = comparisonexamples *did not cure **partially cured MnNaph—Manganese(II)naphthenate Mn2-EH—Manganese (II) 2-ethylhexanoateMn(II)AA—Manganese(II) acetylacetonate Mn(II)HFAA—Manganese(II)hexafluoroacetylacetonate Mn(III)AA—Manganese(III) acetylacetonateMn(III)TMH—Tris(2,2,6,6-tetramethyl-3,5-heptanedionato)manganese(III)Evaluation of Mn(III)AA in Representative Formulations:

Mn(III)AA of example 9 compared to Mn (II)AA of example 5 shows ashorter TFT and shorter time for complete cure, and was found to be oneof the effective catalysts among different manganese complexes screened.Mn(III)AA is evaluated in selected representative formulations. (Theformulation details of (a) (b), (c), (d), (e) and (f) are identified inTable 1 above). Table 3 below summarizes the results.

TABLE 3 Complete Formu- Catalyst Curing lation amount TFT Color of Colorafter after Example 100 g Catalyst (in g) [min] formulation cure [days]C1 a DBTDL 0.2 14 Colorless Colorless 1 C2 a DBTDL 0.4 14 ColorlessColorless 1  9 a Mn(III)AA 0.2 2 Brown Brown 1 10 a Mn(III)AA 0.4 2Brown Brown 1 C3 b DBTDL 0.1 480 White White 1 C4 b DBTDL 0.2 300 WhiteWhite 1 13 b Mn(III)AA 0.1 2880 Grey Grey  >7 * 14 b Mn(III)AA 0.2 <1440Grey Grey   1 ** C5 c DBTDL 0.2 240 Red Red 1 C6 c DBTDL 0.4 180 Red Red1 15 c Mn(III)AA 0.2 — Red Red   1 ** 16 c Mn(III)AA 0.4 120 Red Red 1C7 d DBTDL 0.02 10 Translucent White   3 ³ C8 d DBTDL 0.1 10 TranslucentWhite   3 ³ C9 d DBTDL 0.2 5 Translucent White   3 ³ 17 d Mn(III)AA 0.150 Pale brown Tan   3 ³ 18 d Mn(III)AA 0.2 45 Brown Tan   2 ³  C10 eDBTDL 0.2 1200 Translucent Colorless 1  C11 e DBTDL 0.4 300 TranslucentColorless 1 19 e Mn(III)AA 0.2 — Brown — >7 ⁴ 20 e Mn(III)AA 0.4 — Brown— >7 ⁴  C12 f DBTDL 0.4 120 Colorless Colorless 2  C13 f DBTDL 0.8 120Colorless Colorless 1 21 f Mn(III)AA 0.4 60 Blackish brown Pale brown 122 f Mn(III)AA 0.8 240 Blackish brown Brown 1 * some uncured at thebottom ** sticky # 2.5 mm thickness ³ 1 cm thickness ⁴ did not cure

Comparative Examples C1-C2 describe evaluation of formulation (a) withDBTDL and Examples 9-10 describe evaluation with Mn(III)AA. While theDBTDL containing formulations had a TFT of 14 minutes, the Mn(III)AAcontaining formulations had a TFT of 2 minutes. The bulk curingcharacteristics of both the DBTDL and the Mn(III)AA containingformulations are found to be comparable.

Comparative Examples C3-C4 and Examples 13-14 describe evaluation informulation (b). While, the TFT observed for DBTDL catalyzed curing istypically in the range of 5-8 hours, a complete curing is evident in aday. In comparison, a retardation of curing is evident in case ofMn(III)AA containing formulation (Examples 13-14), as it is evident froma significantly higher TFT (24 hours to 48 hours) and such observationis related to the presence of water (which is added to accelerate theorganotin catalyzed moisture curing) in formulation (b). Hence, itappears that with the use of Mn(III)AA as a condensation cure catalyst,the necessity of faster cure speed may be achieved with the employmentof higher loading of the catalyst and not with the addition of water.Similarly, DBTDL containing formulation (c) had a TFT of 3-4 hours andcomplete bulk cure time of 1 day (Comparative Examples 5-6). Mn(III)AAcontaining formulation (c) had TFT in the range of 120 min andcompletely cured in 1 day (Examples 15-16). While the TFT of DBTDLcontaining formulation (d) (Comparative Examples 7-9) are in the rangeof 5-10 min and for the complete bulk curing typically takes 3 days. Incomparison, the TFT values observed for Mn(III)AA containing formulation(d) (Examples 17-18) are around 45-50 min, and the complete bulk curingis evident in 2-3 days.

With respect to moisture curing of dimethoxysilyl stoppedpolydimethylsiloxane (formulation (e)), the Mn(III)AA containingformulations did not exhibit any curing and such behavior is ratherrationalized to the presence of amine impurities present in thedimethoxysilyl stopped polydimethylsiloxane and no additionalcrosslinker (B) was used (Examples 19-20). Experiments with Mn(III)AA innon-silicone resin (formulation (1), silylated polyurethane (SPUR))showed TFT˜60-240 min and complete cure in 1 day (Examples 21-22) ascompare to DBTDL having TFT of 2 hours and complete cure in 1 day(Comparative Examples 12-13).

Comparative Example 14 (C14)

A mixture of 6.2 g monooctyl phosphate (component (F)) and 8 gmethyltrimethoxysilane (component (B)) was taken in an internal mixerand thoroughly mixed for a period of 5 minutes after which 100 g of a—Si(CH₃)₂OH-capped polydimethylsiloxane (component (A); RTV 89165supplied by Momentive Performance Materials) 50 Pa·s (25° C.) was addedand admixed for a period of 10 minutes. At the end of the mixing step,the viscosity of the mixture increased abruptly to a more viscoelasticbehaviour. After the addition of 0.2 g methanol component (component(G)), the viscosity decreased.

The resulting alkoxysilyl modified polymer was cooled down to 30° C. ina Ross double planetary mixer kettle, and a portion of this polymer wasadmixed with a crosslinker (component (B)),bis(3-propyltrimethoxysilyl)amine as adhesion promoter (component (D)),the trimethylsilyl stopped PDMS as a plasticizer as component (G),hydrophobic fumed silica (BET specific surface area of about 110 m²/gAerosil® R972 supplied by Evonik) as component (E), and dibutyltindilaurate (DBTDL) as a catalyst (component (C)) in the ratio listed intable 4. The reactive mixture was stored under dry nitrogen in a closedcontainer (cartridge with nozzle) prior to cure or submitted to heatageing for the simulation of storage stability (shelf life time) underaccelerated test conditions.

For measuring the cure and hardness properties the composition isdischarged by extruding the reactive composition into a Teflon moldhaving a cavity height of 10 mm. The molds are exposed to ambient airhaving about 50% humidity at 25° C. in order to start continuous cure.

Example 23

Example 23 was prepared using the procedure of Comparative Example C14except that the DBTL catalyst compound of Comparative Example C14 wasreplaced with manganese (III) acetylacetonate as the catalyst component(C).

Comparative Examples 15 (C15) and 16 (C16)

Comparative Examples 15 and 16 are examples that omit the acidicadditive (F). Comparative Example 15 was prepared by adding 39.6 gmethyltrimethoxysilane (component (B)) to 960 g —Si(CH₃)₂OH-cappedpolydimethylsiloxane (component (A)) at 50 Pa·s (25° C.) in a Rossdouble planetary mixer kettle at room temperature (25° C.) and stirredfor 20 minutes. Dibutylamine (0.6 g) was then added to the mixer, andmixing was continued for another 20 minutes. The endcapping process wasstopped by the addition of formic acid (0.2 g). The mixture was stirredand heated up to 60° C. and kept at that temperature for 90 minutes. Thetemperature of the mixture was subsequently raised up to 100° C. andkept at that temperature for another 90 minutes before removing thevolatile by-products with the application of vacuum for a period of 60minutes.

In a next step this alkoxysilyl modified polymer was cooled down to 30°C. in the Ross double planetary mixer kettle and a portion of thispolymer was admixed with a crosslinker (component (B)),bis(3-propyltrimethoxysilyl)amine as adhesion promoter (component (D)),the trimethylsilyl stopped PDMS as a plasticizer (component (G)),hydrophobic fumed silica (BET specific surface area of about 110m²/g—Aerosil® R972 supplied by Evonik) as a filler component (E), anddibutyltin dilaurate (DBTDL) as a catalyst (component (C)) in the ratiolisted in table 4. The reactive mixture was stored under dry nitrogen ina closed cartridge with nozzle prior to cure.

Comparative Example C16 was prepared in the same manner as ComparativeExample C15 except that the DBTDL catalyst compound was replaced withmanganese (III) acetylacetonate as component (C).

TABLE 4 Formulations C14 Ex. 23 C15 C16 Dimethoxysilyl stopped PDMS — —56.2 56.2 Dimethoxysilyl stopped PDMS 56.2 56.2 — — Monooctylphosphate0.25 0.25 — — Methyl stopped PDMS (100 mPa · s) 28.4 28.4 28.4 28.4Methyltrimethoxysilane 2.9 2.9 2.9 2.9 Dibutyltin dilaurate (DBTDL) 0.4— 0.4 — Mn(III)-acetylacetonate — 0.4 — 0.4 Methanol 0.2 0.2 — —Bis(3-propyltrimethoxysilyl)amine 0.8 0.8 0.8 0.8 Aerosil silica R972 1010 10 10 Properties Tack-free time immediately after 66 100 50 110mixing (min.) Bulk cure time immediately after 24 30 24 >48 mixing (h)Tack-free time after ageing at 60 80 20 Gel 100° C. for 15 days (min)formation Bulk cure time after ageing at >24 >24 >24 Gel 100° C. for 15days (h) formationDiscussion of the Results in Table 4

The example in accordance with aspects of the invention using theMn-(III) acetylacetonate catalyst compound component (C)) together withthe phosphate ester (component (F)) shows a sufficient shortTack-Free-Time (TFT) and a short time for curing through the bulk, Theability to cure i.e. TFT and bulk cure time can be maintained even afterstorage over 15 days at 100° C. of the uncured material in a sealedcartridge, whereas Comparative Example 16 that does not include thephosphate ester (as component (F)) shows some weakness in curing afterstorage at 100° C. only a gel-like stage could be achieved in 24 h.Example 23 further illustrates that the tin catalyst can be replaced byMn catalyst.

Examples 24-26 and Comparative Examples C17-C20

Examples 24-26 and Comparative Examples C17-C20 were prepared asRTV-2K-composition including a first part made in a Ross doubleplanetary mixer kettle at room temperature (25° C.) by mixing 663.3 g ofa SiOH terminated polydimethylsiloxane (component (A)) having aviscosity of 4 Pa·s (25° C.) together with 333.3 g of surface treatedfumed silica as a filler component (E).

The second part of the RTV-2K-composition was prepared in a 250 mL glassbulb, whereby 100 g of a polyethylsilicate as a crosslinker (component(P2)) was mixed with 10 g of a catalyst (component (C)), and 50 gbis(3-propyltrimethoxysilyl)amine (component (D)) following theindividual ratios shown in table 5. Examples 24-26 include 3 g of anacidic component (component (F)), which is one of Versatic™ Acid 10 fromMomentive Performance Materials Inc., lauric acid, and steric acid,whereby example 24 shows adhesion to Al and glass and the shortest TFT.Comparative Examples C17, C19, and C20 did not include an acidiccompound, and C19 did not include Bis(3-propyltrimethoxysilyl)amine. TheTFT for C19/C20 at 25° C. are 90/120 min and after heat ageing 70° C. 5days 190/240 min.

The first and second parts are stored in closed containers e.g. metal orplastic cans until use for testing purposes. For measuring the cure andhardness properties, the first and second parts are mixed together in aratio of 100:1.6/1.63 with a spatula and then poured in a plastic moldhaving a cavity height of 10 mm. The molds are exposed to ambient airhaving about 50% humidity at 25° C. in order to start continuous cure.For simulated shelf life tests for the closed metal cans that containsecond part P2 are exposed to the ageing conditions for the giventemperatures of table 5 and unified by mixing in ratios following table5.

TABLE 5 Formulations C17 C18 C19 C20 Ex-24 EX-25 EX-26 Part 1 (P1)OH-end capped PDMS 66.3 66.3 66.3 66.3 66.3 66.3 66.3 Treated fumedsilica 33.3 33.3 33.3 33.3 33.3 33.3 33.3 Part 2 (P2) Ethylpolysillicate 1 1 1 1 1 1 1 Dibutyltin dilaurate 0.1 0.1Mn(III)-acetylacetonate 0.1 0.1 0.1 0.1 0.1 Versatic acid 0.03 0.03Lauric acid 0.03 Steric acid 0.03 Bis(3-propyltrimethoxysilyl)amine 0.50.5 0.5 0.5 0.5 0.5 Properties Tack-free time (min) - immediately after[min] 13 11 90 120 13 20 23 mixing P1 and P2 Bulk care time (h) -immediately after [h] 6 6 12 48 6 8 8 mixing P1 and P2 Shore-A hardness(top/bottom) - ° Shore 58/60 50/55 20/10 30/35 60/57 60/57 60/57immediately after mixing P1 and P2 A Tack-free time (min) - after ageingat 70° C. [min] 17 15 190 240 42 100 110 for 5 days Bulk cure time (h) -after ageing at 70° C. for [h] 6 6 48 52 10 48 48 5 days Shore-Ahardness (top/bottom) - after ° Shore 52/50 50/48 20/12 30/32 40/4525/28 20/25 ageing at 70° C. for 5 days A Adhesion to PVC x x x x xAdhesion to Glass x x + + + Adhesion to PMMA x x x x x Adhesion toAluminum x x + + + x—No adhesion; +—Good adhesionDiscussion of the Results of Table 5

Examples 24-26 shows that the cure behaviour of a RT2K compositionswherein the tin catalysts is replaced by a Mn(III)-acetylacetoantecatalyst and an acidic compound achieve a comparable sufficient degreeof cure rate and a high crosslinking density expressed e.g. by hardness,whereby the adhesion properties are improved when measured in contact toglass and aluminum. In particular example 24 wherein the Versatic Acidwas used the properties are close to the examples using the tin catalystDBTDL. The adhesion promoter of Example 24 works better together with Mncatalyst than together with the tin catalyst of Comparative Example C18when the Versatic acid is also used.

The ability to cure can be maintained even after heat ageing of theuncured composition at 70° C. for 5 days whereby this test is used asaccelerated shelf-life test. The Mn(III) acetylacetonate catalyst showsthe shortest curing times measure as TFT as well for the curing throughthe bulk if Versatic Acid is used (Example 24). If the Mn(III) is usedtogether with the adhesion promoter absent the acidic compound as shownin Comparative Example C20, the cure time is enlarged.

Embodiments of the invention have been described above and modificationsand alterations may occur to others upon the reading and understandingof this specification. The claims as follows are intended to include allmodifications and alterations insofar as they come within the scope ofthe claims or the equivalent thereof.

We claim:
 1. A composition for forming a cured polymer compositioncomprising: 100 pt. wt of component (A) of formulaR² _(3-a)R¹ _(a)Si—Z—[R₂SiO]_(x)[R¹ ₂SiO]_(y)—Z—SiR¹ _(a)R² _(3-a)whereby x is 0 to 10000; y is 0 to 1000; a is 0 to 2; R is methyl; R¹ ischosen from a C₁-C₁₀-alkyl; a C₁-C₁₀ alkyl substituted with one or moreof Cl, F, N, O or S; a phenyl; or a combination of two or more thereof,and other siloxane units may be present in amounts less than 10 mol. %preferably methyl, vinyl, phenyl; R² is chosen from OH, a C₁-C₈-alkoxy,a C₂-C₁₈-alkoxyalkyl, or a combination thereof, and Z is —O—, bond, or—C₂H₄—, 0.1 to about 10 pt. wt of at least one crosslinker (B) selectedfrom a silane, the silane having two or more reactive groups andcombinations thereof, 0.01 to about 7 pt. wt. of a catalyst (C)comprises a Mn(III) complex of the formula:Mn^(III)Y₃ wherein Y is a chelating ligand is a diketonate, 0.1 to about5 pt. wt. of an adhesion promoter (D) selected from anaminoalkyltrialkoxysilane, an aminoalkylalkyldialkoxysilane, abis(alkyl-trialkoxysilyl)amine, a tris(alkyltrialkoxysilyl)amine or acombination thereof, 0 to about 300 pt. wt of component (E) a fillercomponent, 0.01 to about 1.0 pt. wt. of component (F) branched alkylcarboxylic acid, whereby the composition are stored in the absence ofhumidity and is curable in the presence of humidity upon exposure toambient air.
 2. The composition of claim 1, wherein the component (F) ischosen from a branched alkyl C₄-C₁₄-alkyl carboxylic acids or acombination of two or more thereof.
 3. The composition of claim 1,wherein the crosslinker component (B) is chosen fromtetraethylorthosilicate (TEOS), a polycondensate of TEOS;methyltrimethoxysilane (MTMS); a polycondensate of MTMSvinyl-trimethoxysilane; methylvinyldimethoxysilane;dimethyldiethoxysilane; vinyltriethoxysilane;tetra-n-propylorthosilicate; vinyltris(methylethylketoxime)silane;methyltris(methylethylketoxime)silane; trisacetamidomethylsilane;bisacetamidodimethylsilane; tris(N-methyl-acetamido)methylsilane;bis(N-methylacetamido)dimethylsilane;(N-methyl-acetamido)methyldialkoxysilane; trisbenzamidomethylsilane;trispropenoxymethylsilane; alkyldialkoxyamidosilanes;alkylalkoxybisamidosilanes; CH₃Si(OC₂H₅)₁₋₂(NHCOR)₂₋₁;(CH₃Si(OC₂H₅)(NCH₃COC₆H₅)₂, CH₃Si(OC₂H₅)—(NHCOC₆H₅)₂;methyldimethoxy(ethylmethylketoximo)silane;methylmethoxybis-(ethylmethylketoximo)silane;methyldimethoxy(acetaldoximo)silane;methyldimethoxy(N-methylcarbamato)silane;ethyldimethoxy(N-methylcarbamato)silane;methyldimethoxyisopropenoxysilane; trimethoxyisopropenoxysilane;methyltri-iso-propenoxysilane; methyldimethoxy(but-2-ene-2-oxy)silane;methyldimethoxy(1-phenylethenoxy)silane;methyldimethoxy-2(1-carboethoxypropenoxy)silane;methylmethoxydi-N-methylaminosilane; vinyldimethoxymethylaminosilane;tetra-N,N-diethylaminosilane; methyldimethoxymethylaminosilane;methyltricyclohexylaminosilane; methyldimethoxyethylaminosilane;dimethyldi-N,N-dimethylaminosilane; methyldimethoxyisopropylaminosilanedimethyldi-N,N-diethylaminosilane; ethyldimethoxy(N-ethylpropionamido)silane; methyldimethoxy(N-methylacetamido)silane;methyltris(N-methylacetamido)silane;ethyldimethoxy(N-methylacetamido)silane;methyltris(N-methylbenzamido)silane;methylmethoxybis(N-methylacetamido)silane;methyldimethoxy(caprolactamo)silane;trimethoxy(N-methylacetamido)silane;methyldimethoxyethylacetimidatosilane;methyldimethoxypropylacetimidatosilane;methyldimethoxy(N,N′,N′-trimethylureido)silane;methyldimethoxy(N-allyl-N′,N′-dimethylureido)silane;methyldimethoxy(N-phenyl-N′,N′-dimethylureido)silane;methyldimethoxyisocyanatosilane; dimethoxydiisocyanatosilane;methyldimethoxythioisocyanatosilane;methylmethoxydithioisocyanatosilane, or a combination of two or morethereof.
 4. The composition of claim 1, comprising about 1 to about 10wt. % of the crosslinker component (B) based on 100 wt. % of the polymercomponent (A).
 5. The composition of claim 1, wherein the crosslinkercomponent (B) is chosen from a silane or a siloxane, the silane orsiloxane having two or more reactive groups that can undergo hydrolysisand/or condensation reaction with polymer (A) or on its own in thepresence of water and component (F).
 6. The composition of claim 1further comprising a solvent chosen from an alkylbenzene, atrialkylphosphate, a triarylphosphate, a phthalic acid ester, anarylsulfonic acid ester having a viscosity-density constant (VDC) of atleast 0.86 that is miscible with a polyorganosiloxanes and catalystcomponent (C), a polyorganosiloxane devoid of reactive groups and havinga viscosity of less than 2000 mPa·s at 25° C., or a combination of twoor more thereof.
 7. The composition of claim 1, wherein the compositionis provided as a one part composition.
 8. The composition of claim 1,wherein the composition is a two-part composition comprising: (i) afirst portion comprising the siloxane polymer component (A), optionallythe filler component (E), (ii) a second portion comprising thecrosslinker (B), the catalyst component (C), the adhesive promoter (D),and the acidic compound (F) whereby (i) and (ii) are stored separatelyuntil applied for curing by mixing of the components (i) and (ii). 9.The two-part composition of claim 8 where: portion (i) comprises 100 pt.wt. of component (A), and 0 to 70 pt. wt. of component (E); and portion(ii) comprises 0.1 to 10 pt. wt. of at least one crosslinker (B), 0.01to 7 pt. wt. of a catalyst (C), 0 to 5 pt. wt. of an adhesion promoter(D), and 0.01 to about 1 pt. wt. component (F).
 10. A method ofproviding a cured material comprising combining the first portion andthe second portion of claim 8 and curing the mixture.
 11. A method ofproviding a cured material comprising combining the first portion andthe second portion of claim 9 and curing the mixture.
 12. A method ofproviding a cured material comprising exposing the composition of claim1 to ambient air, whereby the composition is stored in a sealedcartridge or flexible bag having outlet nozzles for extrusion and/orshaping of the uncured composition prior to cure.
 13. A cured polymermaterial formed from the composition of claim 1 in the form of anelastomeric or duromeric seal, an adhesive, a coating, an encapsulant, ashaped article, a mold, and an impression material.